Need Help in Small Project

I need help with a small project that I am doing for my client. My clients have a company that does staffing for hotel workers and when they sign up with him, they have to watch 4 separate training videos.
What I need help with is a script of some sort that will pop-up a sign in box of some sort after every video was finished so we can log a record of that person watching each video.
How can I accomplish this with an open source free script?

I found an answer on the first google search: